Apparatus for flattening coldrolled strip metal



Feb, 27, 1951 c. R. WESSMAN 2,543,392

APPARATUS FOR FLATTENING COLD ROLLED STRIP METAL Filed April 2, 1945 2 Sheets-Sheet l Jig. 1.

K j INVENTOR Cor/ REM/z 5/270 Feb. 2?, 1951 c. R. WESSMAN 2,543,392

APPARATUS FOR FLATTENING COLD ROLLED STRIP METAL 2 Sheets-Sheet 2 Jig 4.

Filed April 2, 1945 INVENTOR BY Carl R. Wgs a I k 6 ATTORNE/ Patented Feb. 27, 1951 UNITED APPARATUS FOR FLATTENING COLD- ROLLED STRIP METAL Carl R. Wcssman, Shaker Heights, Ohio Application Aprfl 2, 1945, Serial No. 586,186

1 This invention relates to an apparatus for flat- 1 Claim. (on, 80-51) tening strip metal and more particularly for 'removing the diagonal buckle from strip, metal after the latter has been cold rolled.

In the cold rolling of flat strip metal, particularly the cold rolling of strip steel, it is usually desirable to produce material as fiat as possible. Thus, when a convenient length of such strip metal free from coil curvature or coil set is placed on a perfectl plane surface, th sample should lie very flat on such surface without any portion thereof rising an appreciable distance therefrom.

When made by conventional practice, however,

the strip at finished thickness frequently departs from a perfectly fiat shape and has the characteristics known to the trad as wave and buckle. By wave is meant a sinuous shape along the edges of the strip and by buckle a corrugated or washboard effect along the center of the strip. Either of these conditions is objectionable for the manufacture of fiat articles since an article stamped from wavy or buckle strip will not lie perfectly flat after stamping.

The present invention relates to means for substantially eliminating that kind of buckle in the strip metal which is known as diagonal buckle, that is, one in which the undulations are at an angle of approximately 45 to the direction of rolling of the strip. Such type of buckle, which occurs frequently in the cold rolling of strip steel such as high-carbon steel, has been very troublesome and there has been no satisfactory method for removing it prior to my invention.

The present invention provides a simple, economical apparatus for the substantial elimination of diagonal buckle in cold rolled strip metal. The invention consists generally in the application of an increased tension longitudinally of the strip at the central portion thereof. That is to say, I subject-such central portion of the strip to increased tension by deflecting the strip out of its normal path of travel and bending it about a curved tensioning or guide means as it travels from the cold rolling mill to the coiler or other take-up means.

The invention will be more readily understood by reference to the accompanying drawings, in which:

Figure 1 is a view in side elevation of a cold rolling mill and a coiler, with a strip tensioning or guide means in accordance with the pre ent invention installed on the mill;

Figure 2 is a view in plan of the apparatusshown in Figure l;

Figure 3 is a view in cross section through the mill, taken along the line III--I]I of Figure 2;

Figure 4 is a view in vertical cross section. I

through the mill rolls and strip tensioning means taken along the line IV-IV of Figure 3;

Figure 5 is a view in plan of the tensioning strip engaging guide means;

Figure 6 is a view in side elevation of such guide means; and

Y Figure 7 is an end view of such tensioning guide means.

In the preferred embodiment of the invention which is here illustrated, the tensioning guide means for subjecting the central portion of the strip to increased tension is shown as being mounted upon the rear or exit side of the finishing stand of a conventional cold rolling mill. When so used such tensioning means displays perhaps its greatest advantages, since it is effective to remove diagonal buckle from the strip without requiring any extra handling steps. It is to be understood, however, that the present invention may, in a modification, be carried out as a separate step after the strip has been cold rolled and coiled. For instance, the strip may be uncoiled at a subsequent processing station and pulled so as to subject the central portion thereof to increased tension, while running the strip in contact with the tensioning guiding means of the present invention.

In Figures 1 and 2 the metal strip 2 isshown passing through a cold rolling mill 4 and being taken up on the coiler 6 which subjects it to very substantial tension. This coiler, which is of conventional design, is equipped with a spool or core 8 upon which the strip is wound, driven by gearing, not shown, within housing l0 which in turn is driven by motor l2. Mill 4, which is likewise of standard design, is provided with an upper working roll l4 and a lower working roll l6, both of which are mounted in bearings in the rolling mill housing It.

In the embodiment shown, the central portion of the strip is subjected to increased tension, as compared with the tension applied to the edges thereof, by means of strip tensioning guide 26 mounted on the exit side of the mill. Guide 20,

which may be made of any desired strong material such as wood or metal, and which may have a covering of cloth or felt on at least the strip engaging portion if desired, is preferably a generally fiat shoe having a width slightly less than the width of the strip, as shown in Figure 2, and is supported at an acute angle to the strip of metal issuing from the mill in such manner that the stri rides over the top of the inner end 3 thereof. Guide 20, as shown, is supported in working position by engagement of its outer lower end with a right angular seat 24 in a transverse support 22 which is secured to the mill housings. The inner end of the guide rests on the working face of the lower roll l5. Although such means of support for the tensioning guide means is cheap and simple to provide, it is to be understood that other means may be provided, such as means separate from the rolling mill, if desired. Support 22 forms a convenient means for mounting the wiper 23 for the lower r011 It, as shown in Figure 3.

In order to subject the central portion of the strip to the desired increased tension as compared with the edge portions, the inner stripengaging end or nose of guide 20 is rounded in shape as more clearly shown in Figures 5, 6 and 7. The inner end of the guide is symmetrically rounded in the plane of the upper surface thereof between points a and b on a circular are having a radius R approximately equal to the width of the guide 20, the ends of such arc being connected to the straight sides of the guide by arcs of radius r, radius R being approximately 3 times as great as radius r. In order to present a smoothly changing contour of the guide tothe strip when the guide is positioned with respect thereto at the angle of approximately 30 shown in Figure 3, the upper inner surface of the guide is also rounded in an approximately circular arc as shown in Figure 6. The radius of curvature R of the longitudinal central portion of the front end of means 20 is, in the modification shown, approximately 5 /2 times the thickness T of the guide means 20, the center of such arc lying a distance approximately 3% times T from the end 25 at the longitudinal center of the guide. The inner strip engaging end of guide 20 is further curved, as shown in Figure 7, in an arc transverse to the length of the guide. As shown, the arc is circular and has a radius R" approximately equal to the radius R.

As a result of such configuration, the strip engaging portion of guide means 20 causes the strip immediately upon its issuance from the mill to assume the shape shown in Figure 4, with its central portion deflected furthest upward from the pass 30 of the mill, that is, the normal path of the strip. As there shown, the strip is deflected by gradually decreasing amounts from the center toward the edges, the amount of deflection at the edges depending upon the length of the guide 20 employed and consequently the extent to which the inner edge thereof extends above the pass of the mill. It is usually preferred to design the guide so that the edges of the strip are deflected very little from their normal path of travel as shown in Figure 4.

As a consequence of such bending of the strip and the subjection of the center to increased tension, diagonal buckles, which would normally form on the strip without the presence of the tensioning guide, substantially disappear. The

reason for this is not fully understood, but it is clear that such selective tensioning subjects the strip to a slight amount of cold working, i. e., tensile stress beyond the elastic limit, which decreases in amount from the center to the edges. It is thought that perhaps the formation of dia onal buckles is a function of the central portion of the strip, and that the extra cold working imparted to such portion by the tensioning means gives it added stiffness sufficient to overcome the tendency to buckle. It is not desired, however, that the invention be restricted to such theory of operation.

It is to be understood that the specific angular disposition of the tensioning guide means with respect to the strip, and the specific dimensions and configuration of the guide given above are for the purpose of example only. The guide may be positioned at varying angles with respect to the strip, with the configuration oi. the strip engag-- ing portion thereof modified according provided the guide presents a smoothly curved surface to the strip, such surface serving to subject the strip to a tension, in addition to that contributed by the coiler or other take-up means, gradually decreasing from the central portion of the strip toward the edges thereof over a substantial portion of such central area.

While I have shown and described specific embodiments of the apparatus of my invention, it will be understood that I do not wish to be limited exactly thereto, since various modifications may be made without departing from my invention as defined by the following claim.

I claim:

A buckle-removing guide for a rolling mill adapted to be disposed on the exit side of the mill, said guide comprising a shoe in the form of an elongated flat plate rounded at one end, the upper surface of said end being convexly curved transversely and longitudinally of the plate, the bottom of the plate being fiat and adapted to rest on the body of the lower mill roll and slide thereon when it turns, said rounded end projecting above the horizontal tangent to the top of said roll when the plate is sloped downwardly away from it at a substantial angle to the horizontal, thereby diverting the mid-portion of strip passing through the mill from its normal path immediately on issuing from the mill pass and removing transverse buckle therefrom.

CARL R. WESSMAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,095,733 Coryell Oct. 12, 1937 2,305,793 Puppe Dec. 22, 1942 2,326,470 Lermont et al Aug. 10, 1943 2,469,169 Markle May 3, 1949 

